On Tue, 30 Sep 2014, Kevin Hilman wrote: > On Tue, Sep 30, 2014 at 10:51 AM, Nicolas Pitre > <nicolas.pitre@xxxxxxxxxx> wrote: > > On Tue, 30 Sep 2014, Kevin Hilman wrote: > > > >> Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> writes: > >> > >> > Hi Lina, > >> > > >> > On Sat, Sep 27, 2014 at 01:58:13AM +0100, Lina Iyer wrote: > >> >> Add cpuidle driver interface to allow cpus to go into C-States. Use the > >> >> cpuidle DT interface common across ARM architectures to provide the > >> >> C-State information to the cpuidle framework. > >> >> > >> >> Supported modes at this time are clock gating (wfi) and cpu power down > >> >> (Standalone PC or spc). > >> >> > >> >> Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx> > >> >> --- > >> >> .../bindings/arm/msm/qcom,idle-state.txt | 72 +++++++++++++++++ > >> >> drivers/cpuidle/Kconfig.arm | 7 ++ > >> >> drivers/cpuidle/Makefile | 1 + > >> >> drivers/cpuidle/cpuidle-qcom.c | 89 ++++++++++++++++++++++ > >> >> 4 files changed, 169 insertions(+) > >> >> create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt > >> >> create mode 100644 drivers/cpuidle/cpuidle-qcom.c > >> >> > >> >> diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt > >> >> new file mode 100644 > >> >> index 0000000..47095b9 > >> >> --- /dev/null > >> >> +++ b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt > >> >> @@ -0,0 +1,72 @@ > >> >> +QCOM Idle States for cpuidle driver > >> >> + > >> >> +ARM provides idle-state node to define the cpuidle states, as defined in [1]. > >> >> +cpuidle-qcom is the cpuidle driver for Qualcomm SoCs and uses these idle > >> >> +states. Idle states have different enter/exit latency and residency values. > >> >> +The idle states supported by the QCOM SoC are defined as - > >> >> + > >> >> + * WFI > >> >> + * Retention > >> >> + * Standalone Power Collapse (Standalone PC or SPC) > >> >> + * Power Collapse (PC) > >> >> + > >> >> +WFI: WFI does a little more in addition to architectural clock gating. ARM > >> > > >> > This may be misleading. Call it PlatformWFI or something like that, not WFI if > >> > that's not what it is. > >> > >> This gets at a little pet peeve of mine: > >> > >> IMO, naming any state with "WFI" is a bit confusing, because typically > >> *every* idle state is entered by one (or more) CPU executing WFI, no? > > > > Agreed. > > > > The only state called "WFI" should be the one that only executes the WFI > > instruction without any other hardware setup around it. > > Well, I would go even further in that none of the states should be > called WFI, because WFI is used to enter all of them. Fair enough. So let's fix this by finding a name for that state that consists of only executing WFI and that every SOC has. Suggestions? Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
